plug and play using a delay switch and delay module
the non delay switch plug, plugs into the module and the module plugs into the delay switch. I have tried a few and had no luck getting a good pair (module and switch) when i had my '80
even when they work, they can be very finicky and come on whenever they want

I've had better luck with the newer style with the wipers on the turn stalk
you could build your own circuit
intermittent-wiper-controller